Shroud for an air sander

ABSTRACT

A flexible shroud for an air sander. The flexible shroud has a sealing edge contacting a sanding member of the air sander at a rim of the shroud, wherein the sealing edge is bent inward to form a contact surface in surface contact with the sanding member.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a shroud structure for an air sander,and in particular to an air tool for performing sanding processes in theindustry.

[0003] 2. Description of the Related Art

[0004] An air sander may operate and perform the sanding operation usingcompressed air as a source for driving a sanding member to rotate andutilizing the diflective orbital distance occurred during the rotationof the sanding member. A lot of dust may be generated with the wear-outof the workpiece surface during the sanding operation. Therefore, anewer air sander usually includes a dust collecting means for collectingand removing the dust on the workpiece surface during the sandingoperation.

[0005] Please refer to FIG. 1, which shows a conventional air sander 10having a dust-collecting function as disclosed in U.S. Pat. No.4,531,329. The dust is generated between the sanding member 11 of theair sander 10 and the workpiece surface, so the sanding member 11 isformed with plural apertures 111 serving as suction holes for removingthe dust. In order to prevent the air stream from leaking out and tocollect the dust passing through the sanding member 11, a flexibleshroud 12 is provided to cover the sanding member 11. A contact edge 121is formed at a rim of the shroud 12 so as to contact the outer edge ofthe sanding member 11. Thus, the dust may be collected and removed fromeach aperture 111. There are many contact manners between the contactedge 121 of the shroud 12 and the sanding member 11. For example, thecontact edge 121 may contact the inner edge of the sanding member 11, asshown in FIG. 2. Alternatively, the contact edge 121 may contact theouter edge of the sanding member 11, as shown in FIG. 3.

[0006] It is to be noted that the sanding member usually operates underrotation and vibration or reciprocating movement for a long period oftime, and the contact portion of the shroud may be worn out by thesanding member after a period of time. Hence, the contact portion of theshroud may not tightly contact the sanding member and the dustcollecting and removing effects may be deteriorated because the ambientair may enter the shroud through the contact portion. A significantproblem for this may be found and will be described in the following.Since the contact portion of the conventional shroud contacts thesanding member in the form of a ring-shaped line (or in the form of apoint in the cross-sectional view) and the sanding member operates underreciprocating vibrations, the air-tight effect or dust-suction effect ispoor even if the contact portion of the shroud is slightly worn out.Consequently, the airtight structure between the contact portion of theconventional shroud and the sanding member has to be further improved inorder to meet the requirement in usage.

SUMMARY OF THE INVENTION

[0007] A primary object of the invention is to provide a shroud for anair sander. Good airtight effect may be obtained by forming a contactsurface, which extends from the sealing edge of the shroud and contactsthe sanding member in the form of a plane.

[0008] According to one aspect of the invention, a flexible shroud has asealing edge contacting a sanding member of an air sander at a rim ofthe shroud, wherein the sealing edge is bent inward to form a contactsurface in tight and surface contact with the sanding member.

[0009] Further benefits and advantages of the present invention willbecome apparent after a careful reading of the detailed description withappropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a pictorial view showing a conventional air sander.

[0011]FIG. 2 is a partially cross-sectional view showing the contactrelationship between the sanding member and the contact edge of aconventional shroud for the air sander.

[0012]FIG. 3 is a partially cross-sectional view showing the contactrelationship between the sanding member and the contact edge of anotherconventional shroud for the air sander.

[0013]FIG. 4 is a cross-sectional view showing the contact relationshipbetween the sanding member and the shroud of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0014] Please refer to FIG. 4, which shows the contact relationshipbetween the sanding member and the shroud of the invention. Theimprovement of the invention resides in that the shroud 20 is formedwith a contact surface 211. The shroud 20 is a flexible member made of,for example, rubber. The shroud 20 has a sealing edge 21 contacting thesanding member 30 of the air sander at a rim of the shroud 20. Thesanding member 30 of the air sander is formed with plural apertures 31for sucking and removing the dust on the workpiece surface. Theapertures 31 are positioned inside the sealing edge 21 of the shroud 20.

[0015] In this embodiment of the invention, the sealing edge 21 of theshroud 20 is particularly bent inward to form the contact surface 211.Therefore, when the sealing edge 21 of the shroud 20 contacts thesanding member 30, the contact surface 211 may tightly contact thesanding member 30 in the form of a plane. In brief, the sanding member30 is in tight and surface contact with the sealing edge 21 of theshroud 20 of the invention, as shown in FIG. 4.

[0016] When the air sander performs the sanding operation, the sandingmember 30 rotates at high speed and a micro-vacuum state may occur atthe bottom of the sanding member 30. Since contact surface 211 of thesealing edge 21 of the shroud 20 is in good contact with the sandingmember 30, or the contact surface 211 is in tight and surface contactwith the sanding member 30, the air-tight effect therebetween may not beadversely influenced by the high-speed rotation and vibration of thesanding member 30. Thus, the sealing effect between the shroud 20 andthe sanding member 30 is pretty good, and a good dust-collecting effectmay be obtained accordingly. Furthermore, the airtight effect is freefrom be influenced owing to slight wear-out of the shroud 20 after aperiod of time. Consequently, the shroud 20 and the sanding member 30may always be kept in tight contact with each other and the lifetime ofthe tool may be extended according to the structure design of theinvention.

[0017] While the preferred embodiment of the invention has been shownand described, it will be apparent to those skilled in the art thatvarious modifications may be made in the embodiment without departingfrom the spirit of the invention. Such modifications are all within thescope of the invention.

What is claimed is:
 1. A flexible shroud for an air sander, the flexibleshroud having a sealing edge contacting a sanding member of the airsander at a rim of the shroud, wherein the sealing edge is bent inwardto form a contact surface in tight and surface contact with the sandingmember.